BELL WORK! Look at the Bohr model shown below then answer the following questions in the margin of your composition notebook for today’s notes. How many positively charged particles are there? What element is this? What is this element’s mass number? How many negatively charged particles are there? How many valence electrons are there?

Preparing for TCAP… SPI 0807.9.1 All matter consists of __________. atoms SPI 0807.9.3 Which of the following is a compound? Co, NaCl, Br SPI 0807.9.9 All metals can be found to the ________ of the zig- zag line on the periodic table. left

Periodic Table Race!

Valence Electrons Chapter 12, Section 1 Chemical Bond—an interaction that holds atoms or ions together Valence Electrons—electrons on the outside electron cloud that determines the atom’s chemical properties

Valence Electron Rule: Group 1: 1 valence e- Group 2: 2 valence e- Groups 3-12: Work them out! Group 13: 3 valence e- Group 14: 4 valence e- Group 15: 5 valence e- Group 16: 6 valence e- Group 17: 7 valence e- Group 18: 8 valence e- (except Helium) Helium is full with just two!

HOLD IT UP! A Bohr model or element name will appear on the screen. Place the cards numbered 1-8 face up on your desk. A Bohr model or element name will appear on the screen. Hold up the card that shows how many valence electrons there are. Don’t be the last person in your small group to hold up the correct number. (If you’re last, you get a strike.) Winner = Person with the least amount of strikes.

Sodium 1

Nitrogen 5

4

Helium 2

7

Germanium 4

Calcium 2

1

Argon 8

Hydrogen 1